element-x-android/libraries/maplibre-compose/src/main/kotlin/io/element/android/libraries/maplibre/compose/MapApplier.kt

/*
 * Copyright (c) 2023 New Vector Ltd
 * Copyright 2021 Google LLC
 * Copied and adapted from android-maps-compose (https://github.com/googlemaps/android-maps-compose)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.element.android.libraries.maplibre.compose

import androidx.compose.runtime.AbstractApplier
import com.mapbox.mapboxsdk.maps.MapboxMap
import com.mapbox.mapboxsdk.maps.Style
import com.mapbox.mapboxsdk.plugins.annotation.SymbolManager

internal interface MapNode {
    fun onAttached() {}
    fun onRemoved() {}
    fun onCleared() {}
}

private object MapNodeRoot : MapNode

internal class MapApplier(
    val map: MapboxMap,
    val style: Style,
    val symbolManager: SymbolManager,
) : AbstractApplier<MapNode>(MapNodeRoot) {
    private val decorations = mutableListOf<MapNode>()

    override fun onClear() {
        symbolManager.deleteAll()
        decorations.forEach { it.onCleared() }
        decorations.clear()
    }

    override fun insertBottomUp(index: Int, instance: MapNode) {
        decorations.add(index, instance)
        instance.onAttached()
    }

    override fun insertTopDown(index: Int, instance: MapNode) {
        // insertBottomUp is preferred
    }

    override fun move(from: Int, to: Int, count: Int) {
        decorations.move(from, to, count)
    }

    override fun remove(index: Int, count: Int) {
        repeat(count) {
            decorations[index + it].onRemoved()
        }
        decorations.remove(index, count)
    }
}